"Had circumstances been a little bit different at the time I think that I probably wouldn't have left.

"The fans were brilliant and the boys were great so it's somewhere that I have really fond memories of and I'm looking forward to rekindling that."

Dorn has scored 124 tries in 200 Super League appearances, the bulk of them for London, the club he originally signed for when he left Sydney Roosters in 2004. He also had a spell at Salford City Reds in 2007.

Castleford coach Daryl Powell said: "Luke is a player that I have admired for a long time.

"His ability to play at half-back or full-back is massive and his leadership qualities and experience make him a key recruitment for us next season.

"I look forward to working with a quality individual who I know will drive our standards."

Dorn is Castleford's second confirmed signing for 2014 and is expected to have plenty of company.

Centre Ashley Gibson is joining them from Salford, while a host of other players have been linked with moves to the club.

Dorn is among several men to leave the Broncos, whose future has yet to be determined amid reports that owner David Hughes is considering his position.